Primary treatment for glucose intolerance is strict adherence to a diet which minimizes postprandial glucose response, and in many cases, use of medications (insulin or oral hypoglycemic agents).
Before 1921, starvation was the only recognized treatment of diabetes mellitus (DM). Since the discovery of exogenous insulin, diet has been a major focus of therapy. Recommendations for the distribution of calories from carbohydrate and fat have shifted over the last 75 years. Based on the opinions of the time, the best mix to promote metabolic control are listed in Table 1 below.
Early recommendations limited dietary carbohydrate, because glycemic control was generally better with this type of regimen. However, over the years researchers found that low-carbohydrate, high-fat diets were associated with dyslipidemias and cardiovascular disease, because most high-fat diets consumed in industrialized countries were high in saturated fat. In 1950, the American Diabetes Association (ADA) recommended increasing the proportion of calories provided by carbohydrate to lower cardiovascular risk. While the risk for cardiovascular disease might be diminished by this strategy, research demonstrated that not all persons with DM respond favorably from the standpoint of metabolic control. In addition, the saturated fat being consumed continued to contribute to cardiovascular risk. The ADA""s recommendation to restrict total fat, without regard to type of fat was challenged in the late 1980s by investigators and participants in the National Institutes of Health (NIH) Consensus Development Conference on diet and exercise in patients with type 2 DM. The recommendation of a carbohydrate-rich diet for all persons with DM also was criticized because the theory that high-carbohydrate diets improve glycemic control and insulin sensitivity was not accepted due to inconclusive evidence. The NIH Conference led to the investigation of other dietary therapies, which resulted in a radical change in the 1994 ADA nutrition recommendations. The new ADA guidelines emphasize individualization of diet strategies. The purpose is to achieve optimal glycemic and metabolic control by varying the proportion of calories provided by the macro nutrients. The proportion selected depends on goals for glycemic control, dietary preferences and response to the diet.
The American Diabetes Association (ADA) currently recommends a diet in which protein is the same as that for the general population and accounts for 10% to 20% of total calories. With protein contributing 10% to 20% of the total calories, 80% to 90% of the total calories remains to be distributed between carbohydrate and fat. The carbohydrate/fat mix is individualized according to dietary preference, treatment goals, metabolic control and the presence of other medical conditions. However, the ADA does make a recommendation for the various types of fat in the diet. Specifically, saturated fat should contribute less than 10% of total calories, and polyunsaturated fat contributing no more than 10% of total calories. The remainder of fat calories should come from monounsaturated fat and the daily intake of cholesterol should be limited to less than 300 mg. The recommendation for fiber intake is the same as for the general public with approximately 20 to 35 g/day of dietary fiber from a variety of food sources. The micro nutrient requirements of otherwise healthy persons with DM will likely be met by consuming the amounts suggested by the Reference Daily Intakes (RDIs). The relationship of the minerals chromium and magnesium to management of DM has been the focus of much research. Individuals considered at risk for micro nutrient deficiencies should be evaluated to determine if supplementation is necessary.
Products designed as sole source of nutrition and as nutritional supplements for the person with diabetes are commercially available. The commercial products are typically liquid and include higher amounts of fat. The higher fat is desired in a liquid nutritional as the fat slows down stomach emptying. Thereby delaying the delivery of nutrients to the small intestine which blunts the absorption curve of carbohydrates after a meal.
Glucerna(copyright) (Ross Products Division of Abbott Laboratories, Columbus Ohio) is a liquid nutritional with fiber for patients with abnormal glucose tolerance. Sodium and calcium caseinates make up 16.7% of total calories as protein; maltodextrin, soy polysaccharide and fructose make up 34.3% of total calories as carbohydrate; and high oleic safflower oil and canola oil make up 49% of total calories as fat. Soy polysaccharide contributes 14.1 g/1000 ml of total dietary fiber. The RDI for vitamins and minerals is delivered in 1422 kcals. The product also contains the ultra trace minerals selenium, chromium and molybdenum and the conditionally essential nutrients carnitine and taurine.
Choice dm(copyright) (Mead Johnson and Company, Evensville, Ind.) is a nutritionally complete beverage for persons with glucose intolerance. Milk protein concentrate makes up 17% of total calories as protein; maltodextrin and sucrose make up 40% of total calories as carbohydrate; and high oleic sunflower oil and canola oil make up 43% of total calories as fat. Microcrystalline cellulose, soy fiber and gum acacia contribute 14.4 g/1000 ml of total dietary fiber. The RDI for vitamins and minerals is delivered in 1060 kcals. The product also contains the ultra trace minerals selenium, chromium and molybdenum and the conditionally essential nutrients, carnitine and taurine.
Resource(copyright) Diabetic (Sandoz Nutrition Corporation, Berne, Switzerland) is a complete liquid formula with fiber specifically designed for persons with type 1 and type 2 diabetes and for persons with stress-induced hyperglycemia. Sodium and calcium caseinates, and soy protein isolate make up, 24% of total calories as protein; hydrolyzed corn starch and fructose make up 36% of total calories as carbohydrate; and high oleic sunflower oil and soybean oil make up 40% of total calories as fat. Partially hydrolyzed guar gum contributes 3.0 g/8 ft. oz. of total dietary fiber. The RDI for vitamins and minerals is delivered in 2000 kcals. The product also contains the ultra trace minerals selenium, chromium and molybdenum and the conditionally essential nutrients carnitine and taurine.
Ensure(copyright) Glucerna(copyright) OS (Ross Products Division of Abbott Laboratories, Columbus Ohio) is an oral supplement specifically designed for people with diabetes. Sodium and calcium caseinates make up 18% of total calories as protein; maltodextrin, fructose, soy polysaccharide and gum arabic make up 37% of total calories as carbohydrate; and high oleic safflower oil and canola oil make up 45% of total calories as fat. Soy polysaccharide and gum arabic contribute 2.0 g/8 fl. oz. of total dietary fiber. At least 25% of the RDIs for 24 key vitamins and minerals are delivered in 8 fl. oz. The product also contains the ultra trace minerals selenium, chromium and molybdenum and the conditionally essential nutrients carnitine and taurine.
U.S. Pat. No. 4,921,877 to Cashmere et al. describes a nutritionally complete liquid formula with 20 to 37% of total caloric value from a carbohydrate blend which consists of corn starch, fructose and soy polysaccharide; 40 to 60% of total caloric value from a fat blend with less than 10% of total calories derived from saturated fatty acids,. up to 10% of total calories from polyunsaturated fatty acids and the balance of fat calories from monounsaturated fatty acids; 8 to 25% of total caloric value is protein; at least the minimum US RDA for vitamins and minerals; effective amounts of ultra trace minerals chromium, selenium and molybdenum; and effective amounts of carnitine, taurine and inositol for the dietary management of persons with glucose intolerance.
U.S. Pat. No. 5,776,887 to Wibert et al. describes a nutritional composition for the dietary management of diabetics containing a 1 to 50% total calories protein; 0 to 45% total calories fat, 5 to 90% total calories carbohydrate system and fiber. The carbohydrate system requires a rapidly absorbed fraction such as glucose or sucrose, a moderately absorbed fraction such as certain cooked starches or fructose and a slowly absorbed fraction such as raw corn starch.
U.S. Pat. No. 5,292,723 to Audry et al. describes a liquid nutritional composition containing a lipid fraction, a protein fraction and a specific combination of glucides useful as dietetics. The glucide fraction consists of glucose polymers and slowly absorbed glucides.
U.S. Pat. No. 5,470,839 to Laughlin et al. describes a composition and method for providing nutrition to a diabetic patient. The low carbohydrate, high fat enteral composition contains a protein source, a carbohydrate source including a slowly digested high amylose starch and soluble dietary fiber, and a fat source that includes a high percentage of monounsaturated fats.
The commercial products listed above begin to address the changing recommendations of the ADA for caloric distribution of persons with DM. The carbohydrate content has been increased slightly along with a corresponding slight decrease in fat, while the fat systems have been modified to decrease the contribution of saturated fatty acids. However, the caloric contribution of the fat remains above the ADA recommendations. The prior art also describes complex multi-component carbohydrate systems which blunt the glycemic response by requiring three or more sources of carbohydrate that are absorbed at different rates. These complex multi-component carbohydrate systems possess physical characteristics which make incorporation of the carbohydrate systems into nutritional formulas difficult. Additionally, these complex multi-component carbohydrate systems are often found to possess unacceptable organoleptic characteristics.
Thus, a need has developed in the art for a simple two component carbohydrate system which acts to blunt the glycemic response of readily absorbed carbohydrates. Particularly, a need has developed in the art for a nutritional product which provides nutrients to a person with abnormal glucose tolerance that also adheres to the ADA recommendations for fat.
The present invention is directed to a two component carbohydrate mixture that solves a number of problems associated with the prior art complex multi-component carbohydrate systems designed for the diabetic. The two component carbohydrate mixture of this invention utilizes a source of fructose in combination with at least one readily digestible glucose polymers. The use of the fructose in the two component carbohydrate mixture significantly decreases the glycemic response when compared to, the glucose polymer alone. Further, this two component carbohydrate mixture tastes good and possesses physical properties which allow for easy incorporation into liquid, powder, bars and semisolid nutritionals.
Additional components may be added to the two component carbohydrate mixture to form a xe2x80x9ccarbohydrate systemxe2x80x9d. This carbohydrate system optionally incorporates nonabsorbent carbohydrates, dietary fiber and indigestible oligosaccharides, thereby increasing fecal bulk, modifying the transit time of nutrients through the intestines and providing nutrients to the beneficial microflora of the large intestine which all contribute to a healthy gastrointestinal tract.
The present invention is also directed to a new nutritional product designed for the person with diabetes that solves a number of problems associated with the prior art nutritional formulas. Since the aim of diabetic therapy is to prevent large fluctuations in blood glucose throughout the day, diabetics are advised to select carbohydrate foods that minimize blood glucose level after a meal by emphasizing the complex carbohydrates (starch) over the simple sugars. Complex carbohydrates are the preferred carbohydrate source as they are considered to be digested more slowly and to raise the blood glucose less than simple rapidly absorbed sugars. The prior art teaches that a complex multi-component carbohydrate system should be used. These systems incorporate differing carbohydrate sources that are digested and absorbed at differing rates. While theses systems produce improved blood glucose levels after a meal, they are difficult to incorporate into nutritional formulas.
The nutritional product of this invention utilizes a two component carbohydrate mixture which includes a source of fructose in combination with at least one readily digestible glucose polymers which the inventors have discovered significantly decreases the glycemic response when compared to the glucose polymer alone. Consequently, a nutritional formula may contain a higher percentage of readily absorbed carbohydrate and produce a lower glycemic response than expected. Further, the additional carbohydrate calories may replace fat calories, thereby facilitating the formulation of a nutritional for persons with diabetes containing less than 37% of the calories from fat.
The present invention is also directed, to a method of delivering nutrients to a person with abnormal glucose tolerance by feeding a nutritional which incorporates the two component carbohydrate mixture and less than 37% of calories from fat.